 export  default function (seconds) {
   seconds = Math.floor(seconds);
   let h = Math.floor(seconds / 3600);
   h = h <= 0  ? '' : `${h}:`;
   let m = Math.floor(seconds / 60 % 60);
   m = m < 10 ? ('0' + m) : m;
   let s = seconds % 60;
   s = s < 10 ? ('0' + s) : s;
   return `${h}${m}:${s}`;
 }